Machines, for example wheel loaders, track loaders, backhoes, and hydraulic excavators, mining shovels, electric rope shovels, draglines, and continuous miners are commonly used for excavating, mining, and material moving applications. Such machines generally include a ground engaging tool having a ground engaging surface that is configured to contact the material. During use of the ground engaging tool, the contacted material abrades the ground engaging surface of the tool. The abrasion results in wearing of the ground engaging surface. As a result, the ground engaging tool and/or a wear member that is part of the ground engaging tool often will be formed so as to be removable from the machine. Either the entire ground engaging tool or the wear member may be replaced on a periodic basis.
The ground engaging tool or its wear member may be replaced when it is determined that wear has occurred beyond an acceptable limit. The determination of when sufficient wear has occurred to indicate the need for replacement typically may be made by service personnel called out to inspect the machine. The determination may be made by visual inspection and measuring the dimensions of the ground engaging tool manually. The measured dimensions then may be compared to the acceptable limit, and selectively replaced based on the comparison. This process of determining when to replace the tool or wear member can be time consuming, labor intensive, and inaccurate.
Tool wear may have multiple consequences. For example, significant wear of one or more ground engaging tools may decrease the efficiency of a machine. Large machines may have large ground engaging tools of substantial weight, for example weights in hundreds of pounds or kilograms. Such large ground engaging tools add substantial cost to maintaining a machine at a large excavating or material moving site such as a quarry, since heavy use in highly abrasive materials may cause significant wear in a short period of time, for example a matter of days or even hours. In addition, heavy wear may cause tool failure, and where the machine is operating in conjunction with a crusher, a failed tooth may accidently be dumped into the crusher and cause serious damage. This may in turn cause significant down time and expense to the entire operation.
One way to measure tool wear is described in U.S. Patent Application Publication 2014/0311762 of Behmlander et al. that was published on Oct. 23, 2014 (“the '762 publication”). Specifically, the '762 publication discloses a sensor imbedded within a cutting edge of a ground engaging tool to measure the length of the tool. The sensor disclosed in the '762 publication is ultrasonic, and generates high frequency sound waves within the cutting edge and evaluates a resulting echo received back by the sensor. A calculation of the time interval between generating a sound wave and receiving an echo gives an indication of the length of the cutting edge. Comparison with a threshold length, in turn, gives an indication of the reduction in length and thus the amount of erosion that has occurred.
Although the wear sensor of the '762 publication may offer a way to monitor decrease in tool length, it's indication of wear may be improved upon. In particular, while the sensor of the '762 publication may provide a significant indication of wear by measuring a decrease in tool length, wear may occur in ways other than a decrease in length of a tool. For large ground engaging tools in heavy use with highly abrasive materials, wear may include alteration of the surface of the ground engaging tools in other ways. A measure of tool length may not necessarily give an indication of breakage of portions of the tool, a decrease in width or thickness of the tool, or other significant alterations of the working surface of the tool. Furthermore, while data on decrease in tool length may give excellent information relevant to strategic development of some tools, it may be beneficial to have data for other wear patterns in order to give additional indications of where the application of tougher alloys and/or hard facing materials may extend tool life.
The topographic wear monitoring system of the present disclosure addresses one or more of the needs set forth above and/or other problems of the prior art.